/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.predictionio.examples.friendrecommendation

import org.apache.predictionio.controller._

// For random algorithm
import scala.util.Random

class RandomAlgorithm (val ap: FriendRecommendationAlgoParams)
  extends LAlgorithm[FriendRecommendationTrainingData,
    RandomModel, FriendRecommendationQuery, FriendRecommendationPrediction] {

  override
  def train(pd: FriendRecommendationTrainingData): RandomModel = {
    new RandomModel(0.5) 
  }

  override
  def predict(model: RandomModel, query: FriendRecommendationQuery): 
    FriendRecommendationPrediction = {
    val randomConfidence = Random.nextDouble
    val acceptance = randomConfidence >= model.randomThreshold
    new FriendRecommendationPrediction(randomConfidence, acceptance)
  }
}
